Pilot burners



May 23, 1967 B. G. CRANNELL ETAL 3,320,943

PILOT BURNERS Filed Sept. 30, 1954 51* ,32 f I l 3 Sheetlsheet lINVENTORS.

@m 6. @Wy/zeig 7 mm -d/ ATTORNEYS.

May 23, 1967 B. G. CRANNELL ETAL. 3,320,943

PILOT BURNERS Filed sept. so, 1964 s sheets-sneer 2 74 anni aan Mlnc0600 0MM nua Naw 00W May 23, 1967 B. G. CRANNELL ETAL ,f 3,320,943

PILOT BURNERS Filed Sept. 50, 1964 3 SheetsSheet 5 .gft-daz (f7/me@ /2/.98

y, ATTORNEYS.

United States Patent O 3,320,943 PILOT BURNERS Brian G. Crannell,Riverdale, and Norman R. Shelton,

Evergreen Park, Ill., assignors to Harper-Wyman Company, Chicago, Ill.,a corporation of Illinois Filed Sept. 30, 1964, Ser. No. 400,525 9Claims. (Cl. 126--39) The present invention relates to pilot burners forgas ranges equipped with oven and broiler burners and has for itsprimary object the provision of a new and improved standing (or standbyor continuous) gas pilot burner for a range having a singlecompartment'with a broiler burner above another burner, such as an ovenburner.

Domestic gas ranges with a Single bake-broil compartment have recentlybecome quite popular. There are several reasons for this popularity. Oneis the more economical construction resulting from the use of a singlecompartment or cavity, which eliminates the conventional broiler drawerbelow the bake burner. Another is a greater exibility in design beca-usethe compartment can be located above the top burners. Also, twobake-broil units can readily be built into the range. Furthermore, thebroil burner can be located at the iupper side of the oven compartment,where it is more readily accessible for visual observation as through awindow in the door.

Heretofore, ranges equipped with a single compartment and having a broilburner above the bake burner required either manual or electricignition, with the attendant disadvantages of inconvenience, complexityand added cost.

Attempts to use standing or continuous gas pilots with an upper broilburner heretofore have been unsuccessful because of extinction of thepilot burner flame resulting from contamination of combustion supportingair byproducts of combustion from the lower bake burner and from an airpressure or concussion wave when the oven door was closed or slammed.This extinction most likely occurred during the oven warm up period,prior to establishment of good ue action.

The present invention provides a new and improved standing gas pilotburner for the upper broiler burner located in the same compartmentabove an ove-n burner in which ignition is maintained despite thepresence of contaminating combustion products and concussion resultingfrom door slam. The pilot burner is of the primary aerated type. Itobtains the required primary air from an air inlet located in a regioncommunicating with the compartment and spaced from the -oven burnerilame combustion products where the air is substantially uncontaminatedand where the lair inlet is subjected to much the same air pressure waveand fluctuations as the pilot burner and the construction of the burneris such that ignition is adequately and effectively maintained.

Accordingly, it is a further object of the present invention to providea new and improved standing gas pilot burner for the ignition of abroiler burner located at the upper side of a compartment at the lowerside of which is located a bake burner and which is supplied withprimary air for aeration from a region remote from the bake burner llamecombustion products but communicating with the compartment and which isso constructed and arranged that it will not be extinguished bycontaminating products of combustion and pressure of concussion wavesresulting from closing or slamming of the compartment door.

The inlet region most conveniently may be in the oven compartment belowthe bake burner flames or at the rear of and at about the level of thebake burner flames.

Another object of the present invention is the provision of a new andimproved standing gas pilot burner which is characterized by a stableand well maintained ignition ICC dame under adverse conditions such ascaused by a pressure or concussion wave occurring upon slamming of anoven door.

A further object of the present invention is the provision of a new andimproved pilot burner of the type described above characterized by atubular construction with a pinched portion adjacent a gas dischargeopening at a point intermediate the ends of the burner whereby there isproduced a well aerated good solid and hard ame having opposedself-impinging portions, one of which is in the nature of a tongueextending into and dividing an opposed portion into two parts.

In brief, the standing or continuous pilot burner of the presentinvention is of the primary aerated type and which is located inignition relation with a broiler burner located at the upper side of adomestic gas range compartment at the lower side of which is located abake burner. The primary air for the pilot burner is obtained from aregion where the air is substantially uncontaminated by products lofcombustion emanating from the bake burner, this region being remote fromthe bake burner llame combustion products and one having communicationwith the compartment. One such region can be, for example, below thelevel of the llames or it can be otherwise located as near the level ofthe flames but where an adequate supply lof uncontaminated air isavailable during the heat-up period. The communication insures that itwill be subject to a pressure wave or concussion created lby the closingor slamming of the compartment or oven door substantially the same asthe one acting upon the standing pilot burner. The arrangement is suchthat both the air inlet and the burner are acted upon by the pressurewave whereby the effects of the pressure wave are substantiallyneutralized and the pilot burner llame is maintained. Furthermore, thepilot burner is of a novel construction comprising a tube ofsubstantially uniform diameter having a pinched portion between its endsand at the downstream end of the pinched portion there is provided anopening through which the gas is discharged and the flame is maintained.The configuration is such rthat there is a primary ow of gas from theinlet and other tube through the opening, which ilow is substantiallycentral of the tube because of the pinched construction. There is also'another a-nd opposed ow of gas from the outer end of the tube, which isclosed, so that there is a wider tiow of gas opposed to the centraltongue-like portion. The result is a flame, having in effect opposingparts one of which is a single central tongue and the other of which isan opposed flame forked by the first. As a result, a hard solid and wellaerated ilame with excellent llame maintenance and stability is achievedso that the standing pilot remains ignited in spite of its being locatedin a region in which products of combustion from the lower bake burnermay be present and which is subject to a pressure wave occurring uponclosure of the oven door.

Other objects and advantages of the present invention will becomeapparent from the ensuing description of an illustrative embodiment inthe course of which reference is had to the accompanying drawings:

FIG. 1 is a front elevational view of a domestic gas range (with doorand front panel omitted) having a single compartment with a lower bakeburner and an ,upper broiler burner and equipped with ignition meansincluding the standing or continuous pilot burner of the presentinvention;

FIG. 2 is an enlarged fragmentary view of the lower part of the rangeillustrated in FIG. 1 and depicting the bake burner;

FIG. 3 is an enlarged vertical cross sectional view, partly broken away,and taken along the line 3-3 of FIG. l;

FIG. 4 is an enlarged fragmentary horizontal cross sectional view,partly in section, taken along the line 4-4 of FIG. 3 and illustratingthe standing pilot burner of the present invention;

FIG. 5 is a perspective view of the standing pilot burner;

FIG. 6 is a fragmentary top plan view :of a portion of the standingpilot burner and illustratingthe nature of the ignition llame providedby the pilot burner;

FIG. 7 is a side elevational view of the flame shown in FIG. 6;

FIG. 8 is a transverse cross sectional view along the line 8 8 of FIG.7; and FIG. 9 is a fragmentary view similar to a portion of FIG. 3,illustrating a different location of the air inlet.

Referring now to the drawings, the invention has been illustrated inconjunction with a domestic g-as range indicated as a whole by referencecharacter 10. The range is characterized by the provision of a singlecavity or compartment 12 at the lower region or side 12A of which ismounted a bake burner 14 and at the upper region of the oven cavity 12Bof which is provided a broil burner 16. These burners may be ofconventional construction and mounted in suitable manner in thecompartment as by the supports 18 at the front ends of the burners andsupports 20 at the rear. The burners are provided with conventionallaterally disposed discharge ports 22. Above each burner is a llameshield 24 (suitably supported, in a manner not shown) and thecompartment is also provided with an oven bottom 26 which is spaced fromthe sides of the oven as by the spaces or openings 28, see FIG. 2, or`by a series of spaced apertures so that the region 12A underneath theoven burner is in good communication with the upper part and will besubject to substantially the same pressure that exists in the ovencavity portion 12B above the bottom 26 as well as being subject to thesame pressure fluctuations and concussion or pressure waves.

The range includes a top burner section 30 including a number of topburners (not shown) having individual controls 32 accessible at theupper portion of the front of the range. The top burner section isisolated from the compartment 12 by heat insulating wall panel 34.

The range has a lower front panel 36 that is either detachably orpermanently secured in place. The panel has a plurality of air vents 38at its lower side disposed above the bottom wall 40 and below a falsebottom 42 spaced a short distance above the bottom 40, which may have aplurality of air vents 43 therein.

The range also has an insulated -rear panel 44 having a flue opening 46therein at its upper end providing cornmunication from the upper end ofthe compartment 12 to atmosphere.

The range is also provided with a bottom hinged door 50 having a glasspanel S2 therein. The Idoor is mounted in conventional manner above thelower front panel 36 and provides access to the interior of compartment12 and the panel enables the user to View the interior of the oven. Thecompartment may be provided with -a series of adjustably mounted shelvesin known manner but which have not been illustrated and which are usedfor supporting goods to be baked or broiled.

Gas is supplied to the burners 14 and 16 through mixing tubes 60 andconduits 62 in conventionl manner. The lower bake burner 14 hasassociated with it a conventional non-aerated standing pilot 64, athermostat controlled heater pilot (not shown, but corresponding to aheater pilot associated with the broil burner and which will bedescribed later) and a thermocouple 68, all supported on Va bracket 70.The standing pilot is supplied with gas through conduit 72 and theheater pilot through conduit 74.

In accordance with the present invention, the upper broil burner 16 hasassociated with it the novel standing primary aerated pilot burnerassembly of the invention, indicated as a whole by reference character80, and

including a tube 82 having a novel port structure 84 and supplied withprimary air through conduit 86 having an air inlet 88 at a regionsupplied with uncontaminated air from below the bake burner 14 as fromthe lower compartment region 12A and as best shown in FIG. 3, whichregion is subject to the substantially same pressure fluctuations andconcussion waves las the flame at the pilot burner port 84 The locationof the inlet end 88 of the primary air conducting tube 82 is ofimportance and varies in different ranges. However, it should generallybe located below the level of the bake burner flames and in a lregionhaving good communication with the region 12B of the oven cavity. The-good communication is effected as by the spaces or openings 28 in theoven bottom 26, or otherwise.

As indicated, tthe primary air supplying conduit 86 extends into and hasits inlet 88 in the compartment portion 12A below the level of theflames issuing from a bake burner 14. The conduit 86 is illustrated inFIGS. 2 and 3 as extending downwardly through the insulated wall panel44 but it may be located otherwise, as in the oven `as shown in FIG. 1.

Referring now more particularly to FIGS. 4 to 8, it will be noted thatthe pilot burner assembly includes the tube 82 which is mounted in abody 90 having a chamber or opening 92 into which the air supply tube 86extends, and in which the tubing is secured in suitable manner, as by apress lit or a threaded fitting of conventional construction, not shown.

Gas is supplied to the standing pilot through the conduit 94 attached toan orice fitting 96 having a through passageway 98 leading to an orificecup 100 with an orifice 102 therein through which the gas is dischargedat a high velocity, thereby to draw uncontamin-ated air from the lowerregion 12A through tube 86 for mixture with the gas in the opening orchamber 92 for discharge into the standing pilot burner tube 82.

The Ipilot burner tube is supported in ignition relation to the broilerlburner 16 by a bracket, indicated as a whole by reference character 104having a generally triangular base portion 106 and an upstandingdiagonal Iportion 108 to which the body 90 is secured as by a nut 110.

The standing pilot burner of the present invention may be used alone, ifdesired. In the illustrated arrangement it is used in known m-anner witha thermostatically controlled heater pilot 112 to which gas is suppliedby suitable control means when the broiler is to be used and having aport 114 through which gas is discharged for transfer of llame from thestanding pilot port 84 to the broiler burner 16. The standing pilot tube82 is disposed substantially horizontally and at 1an angle of about 60relative to the broil burner `and the heater pilot 112 is disposedbetween the broil burner and standing pilot burner 82, also insubstantially horizontal position. Above the heater pilot is athermostatic fluid containing thermosensitive tube 116 heated by flamesissuing from the elongated port 114 and circular ports 118 also providedon 4the heater pilot. Gas is supplied to the heater pilot through a gassupply conduit 120 and the thermosensitive element 116 has a portion116A leading to control apparatus controlling the flow of gas to thebroil burner and effective to `do so when the thermostatic element issufficiently heated 4by the heater pilot 112. In other words, thecontrol is of such character that the standing pilot 80 is continuouslyignited, gas is supplied to the heater pilot under a call for gas bythermostatic control means, such as the oven thermostatic bulb 122 inthe oven and gas is supplied to the broil burner under the control ofthe thermostatic element 116. This type of control is utilized -alsowith the bake burner, although the latter uses a non-aerated pilotburner as previously described.

The heater pilot is supported on the mounting bracket 104 by a part ofthe upstanding portion 108 and the thermostatic element is supported bya generally U-shaped Y. part 123 formed integral with the upstandingportion 108 and by an associated clamping screw 124.

The burner tube 82 has an inlet lor upstream end 132 and a relativelyshort downstream reservoir end 134, which has a closed pinched end 135.

The port 84 is formed by cutting the tube near its downstream end with acutter to provide a semicircular opening at one side of an extending tothe centerline of the tube. The tube is then pinched immediatelyadjacent the upstream end of the port to provide a restricted portion ofreduced width 136 constituted by relatively short, axially, and closelyspaced parallel walls 138. The pinch- 'ing of the tube expands itlaterally at oppositely located portions lof the tube immediatelyupstream of the port. One of the expanded portions, indicated byreference character 140, is located immediately upstream of the port andconstitutes a relatively 'narrow upstre-am facing discharge channel fromthe inlet end 132 of the tube to the port. The opposite expanded portion142 constitutes a downstream gas flow channel from the inlet end to theclosed reservoir 134 of the tube.

The novel standing pilot burner of the present invention provides allame i150, see FIGS. 6 yand 7, having opposed self-impinging portions'152 and 154A, 154B enabling it to remain ignited during operation ofthe oven burner and in the presence of air pressure or concussion wavesresulting from door slam. The flame portion 152 is in the form of acentral upwardly extending tongue and the portion 154 comprises twoforks :154A and 154B formed by the tongue portion 152.

` In an embodiment of the invention that has been constructed and used,the pilot burner tube has an outside diameter of one-quarter inch, alength of 2.563" and the port 84 has been constructed on a centerline.1938 from `the downstream end. The port is cut in the unpinched tubewith a cutter having a radius of .156" and down to the centerline of thetube. After the port has been cut, the tube is pinched at the region 136at the upstream edge of the port so that the outer walls of the tube arespaced apart .125" to provide a space of .062" between the innersurfaces of the walls 138 through which the gas flows. The pinching iseffected by tools providing a radius 'of .094 at the outside of thetube. The blending of the pinched part with the upstream and downstreamends of the tube is effected by rounding a onehalf` inch radius.

. The range is provided at its upper front portion with 'additionalcontrol means for selectively making effective either the bake burner orthe broil burner and means for adjusting the temperature. The means forselecting the burner includes a control knob 160 and the temperaturecontrol includes -a knob 162.

The control may be of known type and it actually constitutes no part ofthe present invention in View of the fact that the pilot burner ignitionof the present invention m-ay be used alone or with various types ofcontrols. In a conventional control, g-as may be continuously suppliedto the standing pilots 64 and 82` through the conduits 74 and 94,respectively. The thermostatic adjustment includes a valve associatedwith temperature control knob 162 and controlled by the oventhermostatic bulb 1.22 which valve, when open, supplies gas to theselector valve 160 and through the latter to the selected bake orbroiler burner. The selector valve also selectively supplies gas to thebake or broil burner; yalthough the ultimate control of gas to suchselected burner is under the control of a valve operated by thethermostatic element 1'16, in the case of the broil burner, and thethermosensitive element 68 in the case of the bake burner. Thus, whenthe oven thermostat calls for heat, gas is supplied to the heaterigniter and the latter is ignited from the standing pilot. After a shortperiod of time, the thermosensitive element, such as 116, associatedwith broil burner 16 heats up and opens a valve to supply gas to thebroil burner and the latter is ignited from the igniter burner. However,as

previously indicated, this type of control need not necessarily be usedas the standing pilot could be used directly to ignite the broil burner.

The standing pilot burner tube 82 has been illustrated ,with the port 84facing upwardly. If desired, the port may face downwardly.

It is believed that the operation of the standing or continuous gaspilot burner assembly i of the present invention will be apparent fromthe detailed foregoing description. In brief, it may be noted that theburner itself can be readily made as a part of a control assembly andthat can be mounted in igniting relationship to a broil burner locatedat the upper side of the oven. compartment. The standing pilot burner8l)` operates when surrounded by an atmosphere including products ofcombustion, that will not support the combustion of a non-aerated pilotor even a primary aerated pilot lthat draws its air from the atmosphere.It draws substantially fresh primary air through tube 86l from alocation 1-2A remote from the combustion product below the level of thebake burner flames and a region where the pressure is substanti-ally thesame and subject to the same fluctuations as the pilot burner. The pilotburner 82 itself is of generally tubular shape with its axis mountedgenerally horizontally and having a single transverse notched port 84generally facing upwardly but which could face downwardly. The notchedport is formed as by a cylindrical cutter at a. right angle to the tubecenterline with its edge intersecting the centerline. The tube is thenpressed or pinched at its centerline, region 136, at the upstream sideof the port to provide short generally parallel walls 138 providingreduced cross section for flow of the air-gas mixture, with the tubebecoming cylindrical again within the length of the port and continuingon the `downstream and with a cylindrical section the end of which isclosed to provide a reservoir 1'34 for air-gas mixture. The mixture inthis reservoir assists in retention of flame at the port 84 in spite ofa concussion wave such as caused by slamming of the oven door. Theparallel walls upstream of the port, in combination with the notch givea target flame effect with a turbulent self-impinging flow pattern withgood flame retention in spite of high primary aeration.

In the modification of the invention illustrated frag- -rnentarily inFIG. 9, the air inlet tube 86 is shown with `an inlet end 88A in adifferent location but one whereat it obtains a supply of substantiallyuncontaminated primary air remote from the products of combustion fromthe bake burner and whereat it is in communication with the ovencompartment so that substantially uncontaminated primary air is suppliedto the pilot burner and whereat the inlet is subjected to the samepressure fluctuations as the pilot burner. Referring now moreparticularly to FIG. 9, it will be seen that the lower oven compartment12A has a rear panel `150 that is inset from the upper portion 1'52 ofthe panel. The air inlet tube 86 extends generally to the level of theburner and the inlet end 88A is to the rear of the burner, whereat thereis available la supply of substantially uncontaminated air suflcient tomaintain the pilot burner 80 ignited during the heat-up period lof thelower burner at 14.

While the present invention has been described in connection with thedetails of embodiments thereof, it should be understood that suchdetails are not intended to be limitative of the invention exceptinsofar as set forth in the claims.

What is claimed as new and desired to be secured as Letters Patent ofthe United States is:

1. In a gas range, a compartment having a door, a lower bake burner anda higher broiler burner wherein combustion products from the bake burnerrise at least to the level yof the broiler burner, a region ofsubstantially uncontaminated fresh air spaced from the products ofcombustion from the bake burner communicating with and subject topressure fluctuations in the compartment, a primary aerated continuousgas pilot burner in the compartment in ignition relation to the broilerburner, and

conduit means communicating with the pilot burner and having an airinlet at said region of fresh air for supplying substantiallyuncontaminated primary air to said pilot burner.

2. In a gas range as claimed in claim 1, wherein said air inlet is inthe compartment located at about the level of and to the rear of thebake burner.

3. In a gas range as claimed in claim 1, wherein said air inlet is inthe compartment located below the level of the bake burner.

4. In a gas range as claimed in claim 1, wherein said pilot burnerincludes a port discharging gas in opposed impinging streams which, whenignited provide opposed impinging tongues of flame.

5. In a gas range as claimed in claim 1, wherein said pilot burnerincludes an orice through which gas is discharged and draws the airthrough said conduit and includes a discharge port through which gas isdischarged in opposed impinging streams which when ignited, provideopposed impinging tongues of flame.

6. In a gas range as claimed in claim 1, wherein said pilot burnerincludes a tube with an inlet portion at its upstream end, a closeddownstream end constituting a gas reservoir section, and a dischargeport between said inlet portion and closed end through which gas isdischarged in opposed impinging streams which, when ignited, provideopposed impinging tongues of llame.

7. In a gas range as claimed in claim 6, wherein said pilot burner tubeincludes a pinched portion immediately adjacent the upstream side ofland in line with the port.

8. A gas pilot burner comprising an elongated tube adapted to be mountedwith its axis generally horizontal and having an upstream inlet end anda closed downstream end, a gas discharge port having an initialsubstantially hemispherical coniiguration at right angles to andextending substantially to the tube centerline, said port being locateda short distance from the closed downstream end of the tube where theclosed end of the tube constitutes a gas reservoir, said tubes having ashort pinched portion adjacent the upstream end of said port and in linewith the port, thereby to provide short generally parallel and fairlyclosely spaced walls yand two: laterally expanded and oppositely locatedportions of the tube immediately upstream of the port, the one expanded45 portion adjacent the port constituting a discharge channel from theinlet end to the port and the other and opposite expanded portionconstituting a gas flow channel from the inlet end to the closed end ofthe tube, whereby gas discharges from the portin two opposed andself-impinging streams, one stream being an outwardly and upwardlyextending tongue-like portion from the discharge channel and the otherbeing an opposed inwardly extending porL tion from the closed reservoirend of the tube forked by the tongue-like portion.

9. In a gas range, a compartment having a door and a lower bake burnerand a higher broil burner, a gas pilot burner in ignition relation tothe broil burner, said pilot burner comprising an elongated tubularelement adapted to be mounted with its axis generally horizontal andhaving an upstream inlet end and a closed downstream end, a gasdischarge port having an initial substantially hemisphericalconfiguration at right angles t-o and extending substantially to thetube centerline, said port being located a short distance from theclosed downstream end of the tube whereby the closed end of the tubeconstitutes a gas reservoir, said tube having a short pinched portionadjacent the upstream end of said port and in line with the port,thereby to provide short generally parallel and fairly closely spacedwalls and two laterally expanded and oppositely located portions of thetube immediately upstream of the port, the one expanded portion adjacentthe port constituting a discharge channel from the inlet end to the portand the other and opposite expanded portion constituting a gas flowchannel from the inlet end to the closed end of the tube, whereby gasdischarges from the port in two opposed and selfimpinging streams, onestream being an outwardly and upwardly extending tongue-like portionfrom the dis- .charge channel and the other being on opposed inwardlyextending portion from the closed reservoir end of the ltube forked bythe tongue-like portion, and conduit means having an air inlet below thelevel of the bake burner flame for supplying primary air to the pilotburner.

References Cited by the Examiner UNITED STATES PATENTS 1,932,740 10/1933Kerr 158-115 X 2,741,302 4/1956 Kile 158-115 3,194,227 7/1965 Beach etal. 158-125 X FOREIGN PATENTS 5 39,364 4/ 1922 France.

FREDERICK L. MATTEsoN, JR., Primary Examiner.

E. G. FAVORS, Assistant Examiner.

1. IN A GAS RANGE, A COMPARTMENT HAVING A DOOR, A LOWER BAKE BURNER ANDA HIGHER BOILER BURNER WHEREIN COMBUSTION PRODUCTS FROM THE BAKE BURNERRISE AT LEAST TO THE LEVEL OF THE BROILER BURNER, A REGION OFSUBSTANTIALLY UNCONTAMINATED FRESH AIR SPACED FROM THE PRODUCTS OFCOMBUSTION FROM THE BAKE BURNER COMMUNICATING WITH AND SUBJECT TOPRESSURE FLUCTUATIONS IN THE COMPARTMENT, A PRIMARY AERATED CONTINUOUSGAS PILOT BURNER IN THE COMPARTMENT IN IGNITION RELATION TO THE BROILERBURNER, AND CONDUIT MEANS COMMUNICATING WITH THE PILOT BURNER AND HAVINGAN AIR INLET AT SAID REGION OF FRESH AIR FOR SUPPLYING SUBSTANTIALLYUNCONTAMINATED PRIMARY AIR TO SAID PILOT BURNER.